Example embodiments relate to a data storage, and more particularly, to an on-board SSD (solid state drive) in which constituent elements are directly mounted on a substrate.
Semiconductor memory devices may be classified into volatile semiconductor memory devices and nonvolatile semiconductor memory devices. Volatile semiconductor memory devices have a high read/write speed but have a disadvantage of losing their stored data when their power supplies are interrupted. Nonvolatile semiconductor memory device retain their stored data even when their power supplies are interrupted. Thus, nonvolatile memory devices are used to remember contents that have to be preserved regardless of whether power supplies are supplied or not.
An example of a data storage using the nonvolatile memory devices includes a solid state drive (SSD). Since a SSD is shipped out in a finished product form by a memory vendor, the SSD can be tested through a joint test action group (JTAG) interface. However, after a controller and a nonvolatile memory device constituting the SSD are individually delivered by a memory vendor, in the case of an on-board SSD being mounted on a board, a JTAG interface cannot be used. Thus, even though a problem occurs in an on-board SSD, a test cannot be performed using an existing JTAG interface. Furthermore, it is practically difficult to embed all test programs in an on-board SSD before delivering constituent elements of the on-board SSD.
Thus, preparing a method capable of executing a test operation with respect to an on-board SSD is being magnified as an important issue.